WASHINGTON (CNN) -- Syrian Ambassador to the United States Imad Moustapha denied accusations that Syria allows foreign fighters into Iraq, calling those claims "preposterous."

In an interview on CNN's Late Edition with Wolf Blitzer, Moustapha said Syria wants to help build a stable Iraq and that "all options are open" with the United States to end the violence there.

Diplomatic relations between the two countries improved this week when Secretary of State Condoleezza Rice met with Syrian Foreign Minister Walid al-Moallem in Sharm El-Sheikh, Egypt for the first high-level talks in more than two years.

"The United States has opened a new phase with us," Moustapha said, "it might be a tipping point in U.S.- Syrian bilateral relations."

When asked about a potential meeting between Secretary of State Rice and Syrian President Bashar al-Assad, he said, "All options are open. We want to engage with the United States."

But Moustapha was critical of the U.S. troops in Iraq, saying that Syria does "not think they are playing a constructive role in the Middle East."

--Late Edition Staff